1. Field of the Invention
The present invention relates to stuffing box packing systems used in industrial pumps, most notably, process or centrifugal pumps. More particularly, the invention controls the rate of water flow, as a function of pressure, to process pump stuffing boxes, in order to optimize the functioning and increase the longevity of the packing around the pump shaft.
2. Description of Related Art
To maintain in good working order the packing or braided, rope-type, packing squares, in the stuffing box around the shaft of an industrial pump has been a persistent problem in the food service, milling, chemical, injection molding, mixing, refinery (grinding) and other industries that move large volumes of material. The packing around the shaft of the pump must be kept moist with water so that the stuffing box serves its intended function to properly cool, lubricate and seal the pump shaft, and protect surrounding parts.
One of the biggest problems in the past has been caused by over-flushing of the packing material, which results in outward migration of elasticizers from the fibers of the packing material. As a result, the packing becomes brittle, loses its own lubricant and ultimately, the packing itself can tear away at the shaft, and must be replaced.
Another problem caused by the over-flushing of water into the packing is that when water leaks out from the packing, it can travel to the gear box, cause bearing failure, with the result that the pumps must then be rebuilt.
Finally, over-flushing of the stuffing box raises economic and ecological considerations, both of which remain a concern with respect to those methods used today for providing water flow to industrial pumps.
Patents directed towards the control of the flow and pressure of water or other fluids, among others, include: U.S. Pat. No. 787,327 issued to G. H. Dworzek, U.S. Pat. No. 1,837,001 issued to J. C. White, U.S. Pat. No. 5,282,493 issued to Schwartz et. al, U.S. Pat. No. 5,771,921, issued to Johnson, U.S. Pat. No. 5,831,158 issued to Schloetterer et. al. and Great Britain Pat. No. 1,565,649.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.